In:
Environmental Science: Advances, Royal Society of Chemistry (RSC), Vol. 1, No. 3 ( 2022), p. 331-341
Abstract:
As a non-actinide fission product of uranium, 137 Cs has a long half-life, high-energy γ-ray emissions, and facile accessibility to ecosystems due to the high solubility and mobility of Cs + ions. Hence, rapid remediation of 137 Cs from radioactive wastewater is an urgent task. Here, we have developed a layered inorganic indium thioantimonate K 2 In 2 Sb 2 S 7 ·2.2H 2 O (KIAS) prepared via cationic substitution from [(CH 3 ) 2 NH 2 ] 2 In 2 Sb 2 S 7 (NIAS) for the efficient enrichment and sequestration of Cs + from complex aqueous solutions. KIAS possesses excellent radiation resistance, hydrolytic stability (In 3+ leaching rates ≤ 0.01% at pH 1–13) and high Cs + adsorption activity. Compared to unactivated NIAS, KIAS has enlarged interlayer spacing and exchangeable interlayer K + ions. It exhibits extremely fast adsorption kinetics towards Cs + with high removal rate (∼93%) in only 1 min, a record for Cs + adsorbents. It also displays high adsorption capacity (309.60 mg g −1 ) and outstanding selectivity for Cs + under the interference of large amounts of alkali (earth) metal ions, anions, and humic acid and even in actual tap water or lake water. Furthermore, KIAS can reversibly trap and release Cs + ions for at least five adsorption–desorption cycles in an easy-to-operate and environmentally friendly elution procedure. The adsorption mechanism of Cs + on KIAS, revealed by batch adsorption experiments and characterizations, is ion exchange between Cs + and interlayer K + ions. This work not only highlights KIAS as a promising Cs + scavenger to minimize contamination in complicated wastewater, but also presents a cation activation strategy to greatly enhance the adsorption performance of layered metal sulfides.
Type of Medium:
Online Resource
ISSN:
2754-7000
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2022
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